The present invention relates to a vibration-damping rubber composition or, more particularly, to a rubber composition useful for shaping a rubber article such as a vibration isolator capable of exhibiting an effect of vibration damping over a wide range of temperatures with improved temperature dependency.
As a material for vibration damping, various kinds of polymeric materials or rubbers are used for the purpose including, in particular, butyl rubbers having good vibration-damping power in comparison with other kinds of rubbers. Butyl rubbers are, however, not quite satisfactory as a vibration-damping material because of the large temperature dependency of the vibration-damping performance to give a limitation in their application to a relatively narrow temperature range. Silicone rubbers, on the other hand, are known to have outstandingly low temperature dependency in many of the mechanical properties while they are little effective as a vibration-damping material. Accordingly, a proposal has recently been made to combine the good vibration-damping power of butyl rubbers and the low temperature dependency of silicone rubbers by blending these two types of synthetic rubbers to obtain a vibration-damping rubber composition usable in a wide temperature range although no quite satisfactory results have yet been obtained in this way.